Deuterium oxide

Membranes were purchased from Oxyphen; NADha was purchased from Alfa Aesar; deuterium oxide was purchased from Deutero; and benzophenone, methylene blue, hydrochloric acid, and copper nitrate were obtained from commercial sources. AGA was prepared according to a published protocol [29 ]. UV-irradiations were carried out using a Hoenle UVACUBE 100 equipped with a 100 W mercury–vapor lamp.

Deuterated methanol (purity 99.8%) and deuterium oxide (99.9%) were supplied from Deutero GmbH (Kastellaun, Germany). Trimethyl silylpropionic acid sodium salt-d₄ (TSPA-d₄), acetonitrile, acetic, formic acids, methanol, and DMSO of the HPLC grade and CDDO-Me were purchased from Merck KGaA (Darmstadt, Germany). Deionized water was purified through Ultrapure Water Systems Arium^® 611DI (Sartorius AG, Gottingen, Germany). Myconoside and calceolarioside E were isolated and purified within the current study. The CDDO-Me and myconoside were dissolved in DMSO, while calceolarioside E was dissolved in methanol. The compounds were then diluted with PBS (pH 7.4) to a concentration of 1 mg/mL, passed through a sterile 20 µm syringe filter (Corning GmbH, Kaiserslautern, Germany), and stored at −20 °C.
Column chromatography (CC) on Polyamide 6 (Fluka, Germany), Sephadex LH-20 and Lobar chromatography (Lobar RP-18, Merck) were used for separation and purification of the individual compounds. Preparative thin layer chromatography (PTLC) was performed on pre-coated plates 60 F254, 0.25 mm and thin layer chromatography (TLC) was performed on 60 F254 plates (Merck). Separation was visualized by spraying with 20% (v/v) H₂SO₄ in an ethanol solution.

8-MOP and 5-MOP were purchased from TCI (Tokyo, Japan, >98%) and TMP from Sigma-Aldrich (Steinheim, Germany, ≥98%). The lyophilized oligonucleotide 5′-(TA)₂₀-3′ was purchased from Sigma-Aldrich. The manufacturer purified the sample by HPLC. Annealing of the oligonucleotide strands in solution was performed within 24 h before the measurements by heating the solution in a water bath up to 93 °C and letting it cool down to room temperature within several hours. Solvents used were pure water (Fisher Chemical, Loughborough, UK, HPLC gradient grade), deuterium oxide (Deutero GmbH, Kastellaun, Germany, 99.9% D) and acetonitrile-d3 (Sigma-Aldrich, ≥99.8% D). Solutions of the oligonucleotides were buffered with PBS (Sigma Aldrich, one tablet dissolved in 200 mL yielded 10 mM phosphate buffer, 2.7 mM potassium chloride, 137 mM sodium chloride, pH 7.4 at 25 °C).

If not stated otherwise, all chemicals were used without further purification. For microgel syntheses N-isopropylacrylamide (NIPAM, 97%; TCI Germany GmbH, Eschborn, Germany) recrystallized from n-hexane (p.a.; VWR International GmbH, Darmstadt, Germany), N-(3-aminopropyl)methacrylamide hydrochloride (APMH, 97%; Sigma Aldrich, Munich, Germany), N,N ${}^{\prime }$ -methylenebisacrylamide (BIS, 99%; Sigma Aldrich) and 2,2 ${}^{\prime }$ -azobis(2-methylpropionamidine) dihydrochloride (V50, 97% granular; Sigma Aldrich) were used. Deuteriumoxide (99.9%) and deuteriumchloride solution (36–38% in D₂O) were purchased from Deutero GmbH, Kastellaun, Germany. Sodium hydroxide solution and hydrochloric acid ( $0.1$ M, Fisher Chemical, Waltham, MA, USA) were used for pH-adjustments, sodium chloride (>99.9%; Carl Roth, Karlsruhe, Germany) was used to alter ionic strength. Water was purified using an Arium pro VF system (Sartorius AG, Göttingen, Germany).